Function elaborate_directives 

pub fn elaborate_directives(
    directives: &[SvaDirective],
    ctx: &ElaborationContext,
) -> Vec<SvaDirective>

Elaborate a set of directives by applying default clocking and disable iff.

IEEE 16.15-16: For each directive:

• If it lacks an explicit clock and a default clocking exists, apply the default.
• If it lacks an explicit disable_iff and a default disable_iff exists, wrap the property body in DisableIff { condition, body }.
• Explicit annotations override defaults (no clobbering).